Heel-base bullet?

This is a UMC round marked .41 SHORT and it has a very short rim with no grove where it joins the case. 9th edition of CARTRIDGES OF THE WORLD list a 41 Short Colt which I assume is the same and describe it as a heel-based bullet. Does this mean that the bullet, not the case rim, somehow holds the cartridge in the cylinder bore and this tiny rim has little or no use?
I have never seen a cartridge rim like this, as I recall. I need a little education on this heel-base concept please.

Here is an explanation and a picture


Thanks Pivi. I have a hard copy of the glossary and read that description but it did not really tell me much, at least what I was expecting. Perhaps my title should have been “Strange Rim?”


There are probably others typing an answer at the same time, but . . .

The 41 Colt is a rimmed cartridge. In the early days of cartridge revolvers it was cheaper and simpler to bore the cylinder straight through and cartridges were loaded with an ouside lubricated bullet that was the same diameter as the case. In the 41 Colt that diameter was about .400". The base of the bullet (heel) was the diameter of the inside of the case.

Later, the cylinders were chambered as they are today, with two diameters. The bullet was then seated inside the case and the diameter was reduced accordingly. Therefore, the .400" became a .385" more or less.

You’ll find the old heel bullets on several cartridges, the most well known being the 22 RF. Most of the CF cartridges use the smaller diameter bullets although you will still find a lot of the old heel-bullet cartridges.


Thanks Ray!

I have been collecting cartridges since I was a “kid”…and have never opened my eyes (or ears) to comprehend a “heel based” bullet. It